// home_2
#include<iostream>

int main()
{
	int n=0;
	double sum=0.0;
	std::cout << "Enter number: ";
	std::cin >> n;

	if( n<0 )
	{
	std::cout << "Enter possitive number: " << std::endl;
	}

	for(int i=1; i<=n; ++i)
	{
		sum+= (  1.0 / i );
	}
	std::cout << sum << std::endl;
	return 0;
}